Perkil8r Posted January 23, 2014 Share Posted January 23, 2014 So for two 8 inch scopes, one at f/5 and one at f/10 (tricky i know), and with eye pieces to produce 100x "magnification", the f/5 image would appear much brighter than the f/10 one? Jd Yes Link to comment Share on other sites More sharing options...
Brantuk Posted January 23, 2014 Share Posted January 23, 2014 You nearly always find that folks imaging dso's with slow scopes have hung a reducer the size of a breeze block off the back end of it lol Link to comment Share on other sites More sharing options...
Orion Posted January 23, 2014 Share Posted January 23, 2014 Could one talk of magnification with respect to a standard camera lens focal length? e.g. if you had a 50mm lens on a camera, then in a reflector with FL 1000mm; at the Newtonian focus, you could say the magnification was 20x ? I.e. 1000/50; (relative to the size if image obtained on film or chip you get just with the camera plus the 50mm lens). Link to comment Share on other sites More sharing options...
philjay Posted January 24, 2014 Share Posted January 24, 2014 Ron, it all depends on what you want to image and also what camera you will be using. For wide vistas the ed80 with a dslr will give excellent account and will indeed gather photons quickly. Add a reducer/flattener and you will go wider and fastet. Without the reducer and a smaller chipped ccd you wont be so wide or fast but it will still be faster and wider than the 100. If you want to go close into galaxies and planetary nebs the 100 at the longer fl will give better image scale but will by its very nature be slower and require more exposure time. Also the 100 will require more accurate guiding Link to comment Share on other sites More sharing options...
+RonC Posted January 24, 2014 Author Share Posted January 24, 2014 Thanks Phil, also would the ED80 be a big improvement over my WO Meg72? Link to comment Share on other sites More sharing options...
Guest Kheldar Posted January 24, 2014 Share Posted January 24, 2014 Thanks Phil, also would the ED80 be a big improvement over my WO Meg72? Made that jump myself, the answer is yes Link to comment Share on other sites More sharing options...
+RonC Posted January 24, 2014 Author Share Posted January 24, 2014 Right that settles it then, an ED80 it is but should I sell or keep the Meg 72 that is now the question? Link to comment Share on other sites More sharing options...
Guest Kheldar Posted January 24, 2014 Share Posted January 24, 2014 Right that settles it then, an ED80 it is but should I sell or keep the Meg 72 that is now the question? Do you have a use for the Meg if you buy the ED? This is my logic ... which explains why I still only have one scope Link to comment Share on other sites More sharing options...
+RonC Posted January 24, 2014 Author Share Posted January 24, 2014 And is a reducer worth getting and why? Link to comment Share on other sites More sharing options...
Guest Kheldar Posted January 24, 2014 Share Posted January 24, 2014 And is a reducer worth getting and why? Yes, makes the scope faster and provides a wider field of view (Use 12string site to check some targets with and without reducer) HOWEVER I would not say it's an essential day one purchase Link to comment Share on other sites More sharing options...
philjay Posted January 24, 2014 Share Posted January 24, 2014 With your Canon as the imaging camera a flattener/reducer will help with getting a nice flat field over the chip of the camera Link to comment Share on other sites More sharing options...
+RonC Posted January 24, 2014 Author Share Posted January 24, 2014 Thanks Stephen Are you' moved in' and settled now? Link to comment Share on other sites More sharing options...
Guest Kheldar Posted January 24, 2014 Share Posted January 24, 2014 With your Canon as the imaging camera a flattener/reducer will help with getting a nice flat field over the chip of the camera Doh, that's the best reason of the lot Phil. Forgot we were talking DSLR here Thanks Stephen Are you' moved in' and settled now? Well we're in Big unpacking effort this weekend Link to comment Share on other sites More sharing options...
+RonC Posted January 24, 2014 Author Share Posted January 24, 2014 Thanks Phil (again) yes DSLR imagaing. So another sale coming up (Meg 72)? Unpacking the worst thing I think!! Missed you last week at WW! Cheers Ron Link to comment Share on other sites More sharing options...
xanthic Posted January 24, 2014 Share Posted January 24, 2014 I realise this is going a bit off-topic, but what are the differences between the mak-newt and a frac imaging-wise? Link to comment Share on other sites More sharing options...
+RonC Posted January 24, 2014 Author Share Posted January 24, 2014 The difference for me Leigh is portability! The MN190 is like a 190mm APO and I love mine but don't want to disturb it from it's set up on the pier but want a good widefield Frac for going out and about! Link to comment Share on other sites More sharing options...
xanthic Posted January 24, 2014 Share Posted January 24, 2014 That makes perfect sense! Link to comment Share on other sites More sharing options...
Teslar Posted January 25, 2014 Share Posted January 25, 2014 What to buy an ED80 Ron? Link to comment Share on other sites More sharing options...
+RonC Posted January 25, 2014 Author Share Posted January 25, 2014 (edited) Yes Tom, if you have got a SW ED80 for sale? Edited January 25, 2014 by Ron Clarke Link to comment Share on other sites More sharing options...
Teslar Posted January 26, 2014 Share Posted January 26, 2014 It certainly is StarWave Link to comment Share on other sites More sharing options...
Johnnyaardvark Posted January 26, 2014 Share Posted January 26, 2014 Some great info here. Out of interest is it not worth Ron keeping the meg 72 for imaging wider fields? Link to comment Share on other sites More sharing options...
+RonC Posted January 26, 2014 Author Share Posted January 26, 2014 He's not Steve, he's just sold it to Felix! Link to comment Share on other sites More sharing options...
Johnnyaardvark Posted January 26, 2014 Share Posted January 26, 2014 Did see your other post actually but didn't know how far you'd got. I'm sure you'll both be very happy! Would have been great to know how they shaped up against each other optically though... quite different focal lengths of course. I also intend to buy the ED80 pro package but am umming and ahrrring (Bit pirate like) as to weather or not it should be my "1st" scope. Link to comment Share on other sites More sharing options...
+RonC Posted January 26, 2014 Author Share Posted January 26, 2014 I'll do a first light report on it at the Badger Farm meet next Saturday Steve (weather permitting!) but ED80 has a FL of 600mm and the Meg72 only 430mm quite a difference! Link to comment Share on other sites More sharing options...
Johnnyaardvark Posted January 26, 2014 Share Posted January 26, 2014 I look forward to your report. Hope you get some clear skies at your meet. Link to comment Share on other sites More sharing options...
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